A metal soap has good solubility in resin and solvent, and has various functions and is used in a wide range of application: a curing accelerator for unsaturated polyester resins, etc., a drier for coating material and printing ink, an adhesive for rubber and tires, an extreme-pressure agent for lubricant oil, a combustion improver, a polymerization catalyst, etc.
However, when a metal soap is used as a curing accelerator under the condition where water exists, the metal soap cannot sufficiently express the function thereof (Non Patent Literature 1).
As a method of solving the problem, a method of using an accelerator aid has been proposed. Examples of the accelerator aid include β-diketones, aromatic tertiary amines, mercaptans (thiol compounds), phosphorus compounds, etc. As a technique using such an accelerator aid, for example, Patent Literature 1 describes the use of a chain transfer agent, such as a thiol compound having a hydrocarbon group with 3 or more carbon atoms, as an accelerator aid in the production of a copolymer for use in a cement admixture that comprises the copolymer as an indispensable component.
Patent Literature 2 describes the use of an accelerator aid, such as aniline derivatives, toluidine derivatives, metal soaps, and thiourea derivatives, in an aqueous resin composition for automotive interior materials, etc.
Further, Non Patent Literature 2 describes the use of a complex of an aromatic tertiary amine and a cobalt salt as an accelerator aid.
Patent Literature 3 discloses a two-component mortar composition suitable for building use, which comprises a resin component containing a norbornene group-containing resin and a methacrylate-containing compound, and a curing agent component containing a peroxide and a thiol.
Since inorganic structures such as concrete structures are deteriorated with the lapse of time after construction owing to neutralization of concrete, brine damage, and freezing damage, maintenance and repair may be required. Concrete structures existing not only in water or seawater but also in tidal area where submerging and drying are repeated by tides is increasingly deteriorated by chlorides in seawater and must be repaired immediately.
As a method for repairing such inorganic structures, the replacement of concrete is general, but in repairing wetted or submerged structures, the part to be replaced must be completely shut out water by covering with a steel sheet pile and then water must be removed from the part, and consequently, the structures are difficult to be repaired.
In the case where concrete or a so-called polymer cement is used for replacing the surface of a structure, an insufficient strength or cracking may be caused at the joint part owing to the difference in the ages of materials. In a more serious case, the part around the repaired part would be rapidly deteriorated because of the flaking of the entire part of the repaired part or the shrinking of the material in the repaired part. In particular, in the case where such repairing is carried out directly in water or seawater without removing water, the water remaining in the joint part would give a fatal risk to structures.
As a method for solving the problem, for example, Non Patent Literature 3 proposes a method of incorporating a filler such as a water-absorbing cement in an adhesive composition serving as a repairing material, or a method of incorporating an amine salt-type surfactant in an adhesive composition to hold water in the surfactant by emulsification.
Patent Literature 4 proposes a method of incorporating a hardly water-soluble organic amine, cement or surfactant in an adhesive composition serving as a repairing material.
Further, Patent Literature 5 proposes a repairing material produced by incorporating a modified silicone resin and an anionic surfactant having a specific structure into an adhesive composition.
Patent Literature 3 proposes a two-component mortar composition suitable for building use, which comprises a resin component containing a norbornene group-containing resin and a methacrylate-containing compound and a curing agent component containing a peroxide and a thiol.
Since concrete structures around seashore, rivers, lakes and the like are in a wet environment in many cases, coating materials applicable even to wet surfaces have been desired. In repairing or constructing indoor structures such as bath rooms, wet areas, water supply systems, and sewerage systems, coating materials to be used are further required to be excellent in showing a certain level of strength even on the surface wetted with dew. In addition, in outdoor structures to be exposed to rain in a heavy daytime traffic area, coating materials that may cure quickly to show a certain level of strength in both dry and wet conditions are desired.
For example, Non Patent Literature 4 describes the cause and phenomenon of discoloration of a coating material comprising an epoxy resin and an amine curing agent and proposes a solution thereof. Non Patent Literature 4 merely describes the method for reducing the discoloration and merely emphasizes that the phenomenon does not influence the long-term properties and that the phenomenon may occur in the surface layer possibly in contact with water. However, it can be easily expected that the blushing phenomenon occurs between the substrate and the coating film when such a coating material is applied on a wet substrate. It would appear from Non Patent Literature 4 that there is no method for thoroughly solving the problem in a coating composition for use on a wet substrate.
Accordingly, just as taught by Non Patent Literature 4, the problem of a blushing phenomenon is enevitable for the adhesion in a wet environment or in a humid environment. This phenomenon occurs when the unreacted amine or the hydrophilic solvent in the composition (coating film) absorbs water to form a hydrate, resulting in the blushing of the coating film surface. This phenomenon detracts from the appearance of cured product and reduced the adhesive properties, and in addition, adversely affect the curing mechanism itself.
As a method of solving these problems, Patent Literature 6 discloses an epoxy resin composition applicable even to a wet surface. Patent Literature 7 discloses a viscous primer composition for sheet lining, which exhibits good curability on a wet surface.
As described above, concrete structures deteriorate through neutralization, brine damage, freezing damage, overaging, etc. In addition, concrete structures may also be damaged by earthquake, collision accident, etc. These deteriorations and damages may cause the spalling of the surface of concrete structures. The spalling of concrete structures has been prevented by a method of applying a curable composition such as a repairing material or the like and curing it and a method of bonding a fibrous sheet to the concrete surface with a curable resin (Patent Literatures 8 and 9).
Metal pipes have bee used in digging a well at the bottom of sea. However, it is expensive and inefficient to transport linear metal pipes to workplaces on the sea. It is also inconvenient and inefficient to remove, store, and transport the metal pipes after the work. Accordingly, the use of fiber-reinforced resin pipes has been considered in place of metal pipes.
In addition, the use of fiber-reinforced resin materials has been considered in the float structures for offshore wind power disclosed in Patent Literature 10, in the floating structures to be constructed according to the method disclosed in Patent Literature 11, and in the underwater structures of the deep sea city project now developing.